Nested Sensor Gauge Carrier Housed in Water Reactive Outer Shell for Smart Zonal Isolation Devices

ABSTRACT

A gauge carrier having a sensor, a ball carrying the sensor, and shell surrounding the ball are disclosed. The sensor can detect at least one of pressure and temperature. The ball exposes a sensor surface to allow fluid to reach the sensor surface to take measurements. The shell, ball, and sensor combined can be configured to float or sink in water. The shell can be made of a dissolvable material that, after dissolving, allows the ball and sensor to float to the surface. The gauge carrier can withstand hydrostatic pressures exceeding 10,000 psi.

BACKGROUND

To perform hydraulic fracturing operations, frac-balls are deployed into an oil well and pumped downhole to seal into frac-valves for zonal isolation so that a target zone can be fractured by pressure pumping appropriate fracking fluids from surface pumps alongside proppants to prevent fracture closure. Conventional frac-balls can be damaged as they are pumped downhole due to the pumped fluid's high velocity in transporting the ball downhole and the ball's own momentum. The damage can cause water hammer effects as the ball impacts onto the valve to abruptly block the flow of the fracking fluid being pumped from the surface. Water hammer effects can produce damaging high-pressure spikes above the hydraulic fracturing valve or the zonal isolation device and falling pressure spikes below the valve. These pressure spikes and abrupt changes in fluid momentum may cause hydraulic and mechanical shock waves to travel along the tubing string resulting in kinking of the tubing, unsetting of a previously set packer, or other types of damage or malfunctions to the well's apparatus, the well's integrity, or damage to the formation itself. Although there have been developments in valve and plug apparatus, unfortunately, they have not adequately addressed the risks from uncontrolled impact of the ball onto the valve, including risks from mechanical shocks or water hammer effects. Consequently, the risks and costs, both in terms of time and money, of such accidents can be considerable.

SUMMARY

Various features of the present disclosure are described herein. To solve the problem of removing the frac-ball to restore flow after the frac operation is completed, various degradable or disintegrable frac-ball materials and their combinations have been used in the prior art; however, the prior art does not address the novel approach disclosed by the present disclosure that achieves the useful mechanical properties and functions required to (1) perform zonal isolation while minimizing mechanical damage due to water hammer effects, (2) measure pressure and temperature data during wellbore stimulation, (3) post stimulation allowing near full bore opening by having the outer water reactive shell dissolve (4) superior predictability of dissolution compared with other offerings (5) release gauge carrier and sensor package, and (6) flow-back of sensor package to surface, enabling retrieval of pressure and temperature data during hydraulic fracturing and analysis to provide valuable information to client.

Embodiments of the present disclosure are directed to a gauge carrier, comprising a ball having an interior volume, an aperture, and a sensor positioned in the interior volume of the ball. The sensor has a sensing surface positioned in the aperture with the sensing surface exposed through the aperture. The gauge carrier also includes a shell configured to substantially surround the ball and to permit fluid to pass through the shell and reach the ball such that the sensor is in physical contact with fluid when the gauge carrier is submerged in the fluid. The shell is made of a dissolvable material, the ball and sensor together are buoyant in water at atmospheric pressure, and the gauge carrier is capable of withstanding hydrostatic pressure of greater than 10,000 psi.

Further embodiments of the present disclosure are directed to a method of obtaining a pressure and temperature profile in a well, including pumping a gauge carrier downhole, the gauge carrier having a sensor and a memory positioned within a ball, wherein the ball and sensor are together buoyant in water at atmospheric pressure, the gauge carrier also having a dissolvable shell. The method also includes upon reaching a desired depth in the well, triggering the dissolvable shell to dissolve, leaving the ball and sensor to float back to surface, and recording data for at least a portion of the time the gauge carrier is in the well.

Still further embodiments of the present disclosure are directed to a method of forming a material comprising forming an alloy from a major constituent and a minor constituent wherein the minor constituent is a rare earth material, adding powder elements to lower stacking fault energy to promote twinning, adding hardeners to promote precipitation to promote strain hardening, and performing post-processing to introduce basal plane surface faults and to homogenize strain hardening.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 illustrates a process by which an alloy with sufficient strength, weight, and other properties is created according to embodiments of the present disclosure.

FIG. 2 is an isometric illustration of a shell according to embodiments of the present disclosure.

FIG. 3 is an isometric illustration of a ball according to embodiments of the present disclosure.

FIG. 4 is a cross-sectional illustration of a gauge carrier including ball and shell according to embodiments of the present disclosure.

FIG. 5 is a view of the gauge carrier shown with the two halves of the shell and the ball open to reveal interior features according to embodiments of the present disclosure.

FIG. 6 shows the shell in an open configuration without the ball according to embodiments of the present disclosure.

FIG. 7 shows an exploded view of the gauge carrier according to embodiments of the present disclosure.

DETAILED DESCRIPTION

Below is a detailed description according to various embodiments of the present disclosure. Embodiments of the present disclosure are directed to the design methodology for a sensor pressure housing to cradle a pressure gauge and memory. In some embodiments, the present disclosure is directed to intelligent material selection and fabrication processes that enable deployment into a wellbore to close a prepositioned frac-plug with a diminished water hammer effect that can damage the frac-valve, damage the tubing string, or unintentionally unset packers or other equipment in the well. The hollow frac-ball is comprised of special alloy materials in a geometry that achieves high strength and ductility with tailorable specific gravity so that the ball's movement downhole and its gentler impact onto the frac-valve can be controlled by surface pumping. In addition, the frac-ball's properties include not only activating, or closing, the valve but also being dissolvable or water reactive to achieve timed and controlled disintegration after completion of the fracking or other downhole operation for which the frac-ball was instrumental, for example as in activating a frac-plug, bridge plug, packer, or flow control device.

The apparatuses, systems, and methods of the present disclosure can be designed using novel alloys which can last in a target environment from days to months and even years, as needed. They are able to successfully work in environments which can include fresh water, complex brines with varying anions and cations to up to point of saturation, inhibited acid or linear, crosslinked gels/fiber containing stimulation fluids, wherein pH of fluid can be very acidic (<1) to very alkaline (>11). The alloy is created using one or more of (1) ingot metallurgy (cast and extrusion), (2) metal matrix composite (ceramic dispersoids of various form factors in monolithic to solid solution or multi-phase metal matrix), and (3) power metallurgy (severe plastic deformation, such as cryogenic milling of powder, equal channel angular processing (ECAP) of solid, high pressure torsion of plates, gradient torsion of tubes, general forging machine operations to cold work alloys, flow-forming and pilgering of tubulars to refine grains, etc.)

FIG. 1 illustrates a process 10 by which an alloy with sufficient strength, weight, and other properties is created according to embodiments of the present disclosure. At 12, a master alloy can be selected which contains a rare earth material as a minor constituent. This is the ingot metallurgy route. An example alloy is a magnesium alloy which has magnesium as the major constituent and with a Gd, Y, Sc, La, Ce, Nd, or any other suitable rare earth material as minor constituent. In some embodiments the rare earth percentage can be between 5-25% by weight. At 14, powder elements are added to lower stacking fault (SF) energy of the alloy. One possible powder element is Ag which lowers the SF energy of the alloy. This material can be referred to as the SF-reducing element or the powder element. In some embodiments the SF-reducing constituent can be between 1-25% by weight. In some embodiments the powder element can be added during degassing. This process may promote twinning of the material.

At 16 hardeners can be added to promote precipitation which will further strain hardening. The hardeners can include Zr or other suitable hardeners which will promote precipitation. The hardeners can be between 0.1-10% by weight. At 18 post processing can be performed, including hot rolling, extrusion, hot forging, or any other suitable hot or cold process. The post processing procedures introduce basal plane surface faults and helps to homogenize strain hardening. Post-processing can include casting a billet to greater than 50% reduction via extrusion. The reduction ratio can be between 25-100,000% or more. Surface faults on basal planes are expected to impede dislocation movement and augment strength and ductility of HCP Mg alloy similar to twinning of FCC metals and alloys. To be noted that as dislocations slip and encounter SF boundaries, they can either (1) cut or interact with SFs' and facilitate plastic deformation or (2) accumulate around SF boundaries and accommodate strain hardening. At 20 the material can be machined using a lathe, mill, or other suitable machining techniques. The resulting material will have sufficient hardness and is sufficiently lightweight to be remarkably pressure-resistant and yet still buoyant in water at standard well pressure values.

Another route to produce a material with the desired properties is the metal matrix composite route in which initially the material is in a powder form before adding rare earth powders. Any rare earth material can be used, including Gd, Y, Sc, La, Ce, Ne, or others. The rare earth fraction can be between 5-25% by weight. The metal matrix composite route can include bulk metallic glass powder(s) (BMGs) routes, including ceramic and BMG dispersoids of various form factors in monolithic to solid solution or multiphase metal matrix. From this point forward the process can be similar to that described in the ingot metallurgy route. At 12 powder elements can be added to lower stacking fault (SF) energy of the alloy. One possible powder element is Ag which lowers the SF energy of the alloy. This material can be referred to as the SF-reducing element or the powder element. In some embodiments the SF-reducing constituent can be between 1-25% by weight. In some embodiments the powder element can be added during degassing. This process may promote twinning of the material.

At 16 hardeners can be added to promote precipitation which will further strain hardening. The hardeners can include Zr or other suitable hardeners which will promote precipitation. The hardeners can be between 0.1-10% by weight. At 18 post processing can be performed, including hot rolling, extrusion, hot forging, or any other suitable hot or cold process. The post processing procedures introduce basal plane surface faults and helps to homogenize strain hardening. Post processing can include casting a billet to greater than 50% reduction via extrusion. The reduction ratio can be between 25-100,000% or more. Surface faults on basal planes are expected to impede dislocation movement and augment strength and ductility of HCP Mg alloy similar to twinning of FCC metals and alloys. To be noted that as dislocations slip and encounter SF boundaries, they can either (1) cut or interact with SFs' and facilitate plastic deformation or (2) accumulate around SF boundaries and accommodate strain hardening. At 20 the material can be machined using a lathe, mill, or other suitable machining techniques. The resulting material will have sufficient hardness and is sufficiently lightweight to be remarkably pressure-resistant and yet still buoyant in water at standard well pressure values.

Yet another route to achieve acceptable properties in the material is a powder metallurgy route in which a metal powder is subjected to severe plastic deformation such as by combustion or another suitable method of combining the powder metals with other constituents. The powder metals are combined with rare earth materials in a way similar to what is described above with reference to the ingot metallurgy route and the metal matrix composite route. For example, At 12 powder elements can be added to lower stacking fault (SF) energy of the alloy. One possible powder element is Ag which lowers the SF energy of the alloy. This material can be referred to as the SF-reducing element or the powder element. In some embodiments the SF-reducing constituent can be between 1-25% by weight. In some embodiments the powder element can be added during degassing. This process may promote twinning of the material.

At 16 hardeners can be added to promote precipitation which will further strain hardening. The hardeners can include Zr or other suitable hardeners which will promote precipitation. The hardeners can be between 0.1-10% by weight. At 18 post processing can be performed, including hot rolling, extrusion, hot forging, or any other suitable hot or cold process. The post processing procedures introduce basal plane surface faults and helps to homogenize strain hardening. Post processing can include casting a billet to greater than 50% reduction via extrusion. The reduction ratio can be between 25-100,000% or more. Surface faults on basal planes are expected to impede dislocation movement and augment strength and ductility of HCP Mg alloy similar to twinning of FCC metals and alloys. To be noted that as dislocations slip and encounter SF boundaries, they can either (1) cut or interact with SFs' and facilitate plastic deformation or (2) accumulate around SF boundaries and accommodate strain hardening. At 20 the material can be machined using a lathe, mill, or other suitable machining techniques. The resulting material will have sufficient hardness and is sufficiently lightweight to be remarkably pressure-resistant and yet still buoyant in water at standard well pressure values.

In some embodiments the material can be created to be dissolvable when subjected to certain conditions. In some embodiments this is achieved by introducing noble granules to the material. This can be done at several different stages of the process. The noble granules render the material dissolvable by introducing failure vectors in the material. When the material is exposed to an environment having the right salinity, pressure, and other chemical properties, the material will dissolve. Accordingly the material can be selectively made to dissolve or not to dissolve as desired. The environment in which the material dissolves can be chosen by altering certain properties of the material and the noble granules. For example, a material with high rate of corrosion (ROC) designed via tailoring the amount of noble particles in metal matrix can be triggered at room temperature in tap water or water with 2500 ppm dissolved salts. On the other hand, materials with low ROC needs elevated temperature in combination with salinity equivalent to sea water or as high as 22% (near saturated or saturated brine) salts to trigger dissolution.

FIG. 2 is an isometric illustration of a shell 30 according to embodiments of the present disclosure, and FIG. 3 is an isometric illustration of a ball 32 according to embodiments of the present disclosure. The ball 32 can be placed in the shell as will be shown below to greater advantage. The ball 32 is shown with a spherical shape; however, it is to be appreciated that the ball 32 need not be spherical and that other suitable shapes are possible within the scope of the present disclosure. The ball 32 and shell 30 can be made of the material resulting from the processes of FIG. 1. The ball 32 can house a gauge such as a pressure and temperature gauge. The ball 32 can have an aperture 34 which is configured to receive the gauge and to allow the environmental fluid to reach the gauge within the ball. The shell 30 includes one or more apertures 36 which allow the fluid to pass through the shell 30 to reach the gauge within the ball 32. The combination of ball and shell can be referred to as a gauge carrier. The gauge carrier is able to withstand hydrostatic pressure of >10,000 psi and is light enough to float in water. The gauge carrier can be deployed into a well and pumped downhole. To retrieve, simply allow the gauge carrier to float back to the surface. The gauge contains a memory which records data for the trip, resulting in a detailed readout of pressure and temperature for the well without the need to pump back to surface or communicate with any other component downhole. In some embodiments the ball 32 is made of material that is not dissolvable and the shell 30 is made of dissolvable material. Also, the weight and density of the shell 30 can be sufficiently high that the ball does not float, allowing the gauge carrier to reach the bottom (or any desired depth) of the well, then dissolve, leaving the ball 32 unharmed and free to float back to the surface.

FIG. 4 is a cross-sectional illustration of a gauge carrier 38 including ball 32 and shell 30 according to embodiments of the present disclosure. The ball 32 and shell 30 are similar to what was shown and described above with respect to FIG. 3. The ball can be made of two hemispheres which can be joined together with threads or another suitable joining mechanism such as welding. An O-ring 40 is shown between the hemispheres to further prevent fluid from entering the ball 32. The ball 32 includes an aperture 34 which can have a threaded interior surface configured to receive a sensor 42. The sensor 42 is therefore housed within the ball 32 with an exposed surface 44 capable of taking readings of such things as temperature, pressure, water cut, flow rate, corrosion, erosion, environmental assisted cracking, dissolved O2, pH, and virtually any other type of sensor. The shell 30 is configured to permit fluid to permeate through to reach the aperture 34 and the sensor surface 44 within. In some embodiments the ball 32 and sensor 42 are light enough to float in water, and yet strong enough to withstand pressures exceeding 10,000 psi. The interior shape of the ball 32 can include a protrusion 46 opposite the aperture 34 which helps increase the ball's resistance to pressure. In some embodiments the thickness of the ball 32 at the protrusion 46 is approximately twice the thickness of the ball 32 elsewhere on the ball. At the aperture 34 the ball 32 also includes a protrusion 47 through which the aperture 34 is formed which can provide a longer threaded surface for improved locking with the sensor 42. The shell 30 can also be lightweight if so desired, or it can be heavier to allow the gauge carrier 38 to sink. In some embodiments the shell 30 is made of a dissolvable material and the combined weight of the shell, ball, and sensor is heavier than water such that the assembly sinks, and the shell (or at least a portion thereof) is dissolvable and at the right conditions will dissolve, leaving the ball and sensor intact and lighter than water such that the ball and sensor will float to the surface after the shell dissolves.

FIG. 5 is a view of the gauge carrier 38 shown with the two halves of the shell 30 and the ball 32 open to reveal interior features according to embodiments of the present disclosure. The shell 30 can include ribs 48 which project inwardly from the interior surface of the shell 30, defining a space 50 between the shell 30 and the ball 32. As shown to greater advantage in FIG. 3, the shell 30 can include apertures which allow surrounding fluid to enter the shell and reach the ball 32 and sensor surface 44 through the aperture 34 in the ball 32. The ribs 48 can be any suitable shape, including a cross-shape as shown here.

FIG. 6 shows the shell 30 in an open configuration without the ball 32 according to embodiments of the present disclosure. The apertures 36 are shown here as well, and the cross-shape of the ribs 48 are shown to greater advantage. Other shapes for the ribs 48 can be used as needed for a given shell configuration.

FIG. 7 shows an exploded view of the gauge carrier 38 according to embodiments of the present disclosure. The components are first shell half 30 a, including apertures 36, first ball half 32 a, including aperture 34, sensor 42, O-ring 40, second ball half 32 b, and finally second shell half 30 b. It is to be appreciated that the gauge carrier 38 is not limited to a spherical shape and that other shapes including an egg shape or a dart shape are possible without departing from the scope of the present disclosure. The gauge carrier 38 need not be constructed in two equal hemispheres; rather, there are other suitable shapes which are within the present disclosure.

The foregoing disclosure hereby enables a person of ordinary skill in the art to make and use the disclosed systems without undue experimentation. Certain examples are given to for purposes of explanation and are not given in a limiting manner. 

1. A gauge carrier, comprising: a ball having an interior volume and an aperture; a sensor positioned in the interior volume of the ball, the sensor having a sensing surface positioned in the aperture with the sensing surface exposed through the aperture; and a shell configured to substantially surround the ball and to permit fluid to pass through the shell and reach the ball such that the sensor is in physical contact with fluid when the gauge carrier is submerged in the fluid; wherein the shell is made of a dissolvable material; wherein the ball and sensor together are buoyant in water at atmospheric pressure; and wherein the gauge carrier is capable of withstanding hydrostatic pressure of greater than 10,000 psi.
 2. The gauge carrier of claim 1 wherein the gauge carrier including the shell is not buoyant in water at atmospheric pressure.
 3. The gauge carrier of claim 1 wherein at least one of the ball and the shell are formed of two hemispheres that are threadably connected.
 4. The gauge carrier of claim 1 wherein the ball includes a protrusion on an interior surface diametrically opposite the aperture.
 5. The gauge carrier of claim 4 wherein the protrusion is approximately twice the thickness of the remainder of the ball.
 6. The gauge carrier of claim 1 wherein the sensor is configured to detect at least one of pressure, temperature, water cut, flow rate, corrosion, erosion, environmental assisted cracking, dissolved O2, and pH, and to store data from measurements taken.
 7. The gauge carrier of claim 1 wherein the shell includes a plurality of projections extending from an interior surface of the shell, wherein spaces between the projections allow fluid to contact the ball.
 8. The gauge carrier of claim 1 wherein the gauge carrier is configured to be pumped down a well and to become situated in a seat, wherein the gauge carrier and seat form a pressure seal sufficient to perform hydraulic fracturing above the pressure seal.
 9. The gauge carrier of claim 1 wherein at least one of the ball and shell are made from a material formed by: forming an alloy from a major constituent and a minor constituent wherein the minor constituent is a rare earth material; adding powder elements to lower stacking fault energy to promote twinning; adding hardeners to promote precipitation to promote strain hardening; and perform post processing to introduce basal plane surface faults and to homogenize strain hardening.
 10. A method of obtaining a pressure and temperature profile in a well, comprising: pumping a gauge carrier downhole, the gauge carrier having a sensor and a memory positioned within a ball, wherein the ball and sensor are together buoyant in water at atmospheric pressure, the gauge carrier also having a dissolvable shell; upon reaching a desired depth in the well, triggering the dissolvable shell to dissolve, leaving the ball and sensor to float back to surface; and recording data for at least a portion of the time the gauge carrier is in the well.
 11. The method of claim 10, further comprising seating the ball in a seat and forming a pressure seal in the well, and performing a hydraulic fracturing operation above the pressure seal.
 12. The method of claim 10 wherein pumping the gauge carrier downhole comprises pumping the gauge carrier to a depth where hydrostatic pressure is greater than 10,000 psi.
 13. A method of forming a material comprising: forming an alloy from a major constituent and a minor constituent wherein the minor constituent is a rare earth material; adding powder elements to lower stacking fault energy to promote twinning; adding hardeners to promote precipitation to promote strain hardening; and performing post-processing to introduce basal plane surface faults and to homogenize strain hardening.
 14. The method of claim J wherein the major constituent comprises at least one of Gd, Y, Sc, La, Ce, or Nd.
 15. The method of claim J wherein the rare earth material comprises between 5-25% of the alloy by weight.
 16. The method of claim 13 wherein the powder material comprises Ag.
 17. The method of claim 13 wherein the powder material comprises between 1-25% of the alloy by weight.
 18. The method of claim 13 wherein the hardeners include Zr.
 19. The method of claim 13 wherein the hardeners comprise between 0.1-10% of the alloy by weight.
 20. The method of claim 13 wherein the post-processing comprises hot rolling, extrusion, hot forging, or any other suitable hot or cold process. 